Pallets are used to store and transport loads of a vast range of goods. For example, a pallet can be used to transport boxes of goods that have been stacked and stretch-wrapped or otherwise secured upon the pallet from a manufacturer to a point of sale. Proper identification of the goods loaded onto the pallet, and of the loaded pallet itself, is critical to assist in proper routing of the loaded pallet within a warehouse or distribution center, and also at a customer's facility.
In the past, printed labels have been applied to loaded pallets that contain label information pertinent to the product or goods loaded onto the pallet, such as the product identification code, pallet identification code, quantity, lot number, customer or order identification data and routing codes. These printed labels have been either affixed to the loaded pallet by hand or, more recently, by semi-automated pallet labeler systems that are capable of applying one or more printed labels to the loaded pallets as the loaded pallets are transported intermittently on a conveyor past the pallet labeler system. Proper positioning of the label on the loaded pallet is important to ensure that the label is not affixed in an irregular area of the loaded pallet or at a position that cannot be read by a scanner or other device that controls routing of the loaded pallet in an automated warehouse or distribution center environment.
More particularly, pallet labeler systems have been developed in the past that are capable of printing labels with pre-selected pallet and/or product identification information and applying printed labels to one side of a loaded pallet at one or more predetermined positions, such as upper and lower label positions on the same pallet load. Prior pallet labeler systems having included a label applicator mechanism that is capable of receiving printed labels from a label printer and transporting the printed labels toward the loaded pallet for applying the printed labels thereto at the predetermined label positions. Positioning of the label applicator mechanism relative to the loaded pallet has been accomplished through a ball screw drive mechanism having electro-mechanical limit switches that set the predetermined upper and lower label positions.
For example, known pallet labeler systems have included a label applicator mechanism that is movable in upward and downward vertical directions under the control of the ball screw drive mechanism. The label applicator mechanism is moved by the ball screw mechanism so as to apply printed labels to the loaded pallet at the predetermined upper and lower label positions. The electro-mechanical limit switches are manually adjusted and set in the ball screw drive mechanism so that the label applicator mechanism will move and stop at the upper and lower label positions when the respective upper and lower limit switches are actuated. However, when label positions are to be changed, such as when a loaded pallet having a different configuration is to be labeled, the limit switches must be manually adjusted and set according to the new label positions. This is not only time consuming and cumbersome, but also severely limits the ability of the pallet labeler system to efficiently label a wide range of loaded pallets having many different predetermined label positions.
In known pallet labeler systems, the printed label is applied to the loaded pallet through a tamp pad that is pivotally mounted on a forward end of an applicator arm. The tamp pad is positioned to receive a printed label from the label printer, and to transport the printed label toward the loaded pallet to apply the label thereto. A photo optic sensor mounted on the tamp pad senses the loaded pallet and is used to retract the tamp pad from the loaded pallet after the printed label has been applied. However, the photo optic sensor used to sense the loaded pallet is prone to cause the tamp pad to retract before the label has been completely applied to the loaded pallet. This may be caused by reflections from the stretch-wrap material or in situations where the stretch-wrap is loosely spaced from the underlying goods. In either case, the photo optic sensor improperly causes the tamp pad to retract before sufficient contact between the label and the loaded pallet has occurred.
The tamp pad in known pallet labeler system includes apertures and bores that are in fluid communication with a vacuum source fluidly connected to the tamp pad through a vacuum hose. An air assist tube emits pressurized air toward the printed label as it separates from its backing web at the label printer to move the label into engagement with the tamp pad. Vacuum pressure is applied to the tamp pad to hold the printed label thereto as the tamp pad is extended toward the loaded pallet to apply the label. However, in the past, the pressurized air source connected to the air assist tube and the vacuum source connected to the tamp pad have each run continuously throughout the entire label printing and application process. As a result, the apertures in the tamp pad tend to become clogged over time with dust and other contaminants and the tamp pad eventually loses its ability to reliably hold the printed labels. Further, a large amount of air is used in the label printing and application process.
Thus, there is a need for a pallet labeler system that is capable of efficiently applying printed labels to a wide range of loaded pallets having many different predetermined label positions.
There is also a need for a pallet labeler system that reliably applies printed labels to loaded pallets with sufficient contact to ensure the printed label is held thereto.
There is yet also a need for a pallet labeler system that uses pressurized air and vacuum sources efficiently during the entire label printing and application process.
There is also a need for a pallet labeler system that is capable of efficiently applying printed labels to multiple sides of a loaded pallet having many different predetermined label positions.